[FIX] models: do not prefetch fields to recompute, and recompute once only

The method _prefetch_field() was accidentally prefetching fields to recompute;
which was skipping the actual recomputation, since a value was put in cache.
But sometimes the field's value was fixed by an extra recomputation of the
field.  Here we remove the extra recomputation and fix the cache corruption.

2 files changed, 22 insertions, 21 deletions

diff --git a/openerp/api.py b/openerp/api.py
index a2385a8b109..da9e62f1549 100644
--- a/openerp/api.py
+++ b/openerp/api.py
@@ -837,11 +837,10 @@ class Environment(object):
 
     def remove_todo(self, field, records):
         """ Mark `field` as recomputed on `records`. """
-        recs_list = self.all.todo.get(field, [])
-        if records in recs_list:
-            recs_list.remove(records)
-            if not recs_list:
-                del self.all.todo[field]
+        recs_list = [recs - records for recs in self.all.todo.pop(field, [])]
+        recs_list = filter(None, recs_list)
+        if recs_list:
+            self.all.todo[field] = recs_list
 
     def has_todo(self):
         """ Return whether some fields must be recomputed. """
diff --git a/openerp/models.py b/openerp/models.py
index 2dcf464a925..1457a4beecf 100644
--- a/openerp/models.py
+++ b/openerp/models.py
@@ -3127,25 +3127,27 @@ class BaseModel(object):
         if len(records) > PREFETCH_MAX:
             records = records[:PREFETCH_MAX] | self
 
-        # by default, simply fetch field
-        fnames = {field.name}
-
-        if self.env.in_draft:
-            # we may be doing an onchange, do not prefetch other fields
-            pass
-        elif self.env.field_todo(field):
-            # field must be recomputed, do not prefetch records to recompute
-            records -= self.env.field_todo(field)
-        elif not self._context.get('prefetch_fields', True):
-            # do not prefetch other fields
-            pass
-        elif self._columns[field.name]._prefetch:
-            # here we can optimize: prefetch all classic and many2one fields
-            fnames = set(fname
+        # determine which fields can be prefetched
+        if not self.env.in_draft and \
+                self._context.get('prefetch_fields', True) and \
+                self._columns[field.name]._prefetch:
+            # prefetch all classic and many2one fields that the user can access
+            fnames = {fname
                 for fname, fcolumn in self._columns.iteritems()
                 if fcolumn._prefetch
                 if not fcolumn.groups or self.user_has_groups(fcolumn.groups)
-            )
+            }
+        else:
+            fnames = {field.name}
+
+        # important: never prefetch fields to recompute!
+        get_recs_todo = self.env.field_todo
+        for fname in list(fnames):
+            if get_recs_todo(self._fields[fname]):
+                if fname == field.name:
+                    records -= get_recs_todo(field)
+                else:
+                    fnames.discard(fname)
 
         # fetch records with read()
         assert self in records and field.name in fnames